From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Letter discussing the final arrangement of a 12-volt auto charge control switch and its benefits over standard charging rates.
| Identifier | ExFiles\Box 43\1\ Scan034 | |
| Date | 29th March 1928 | |
| OY. from EFC. X3988 EFC4/T29.3.28. X4008 We duly received your OY7/R.2.28.28. We arranged with Mr. Nadin that in view of our improvement of the auto switch by which the temperature effect is greatly reduced, we would delay the sending of this U.S.A. switch with the windings as at first arranged until we could incorporate this improvement, which is a distinct one. We have now arrived at the final arrangement of our 12 volt auto charge control switch and hope to be able to specify this exactly for your auto switch during the next few days, when we will give you an amended version of our EFC3/T9.2.28. Possibly the explanation of the statements contained in your second and third paragraphs is that your charging rate in relation to the size of battery is a good deal smaller than our own. The evidence, however, as to just how much charging is required by the battery is rather contradictory, which to my mind is in itself an argument for the use of an auto switch whereby we do not need to know how many ampere-hours of dynamo output are required because the auto switch will do the knowing for us. Our standard charging rate certainly needs a very frequent necessity of topping up during hot weather, resulting to some extent in messing up the top of the battery due to the electrolyte spurting out of the vents. We do not re-set our third brush for winter and summer conditions. It is set to a safe maximum ( in regard to heating), and we prefer the customer not to try to alter it. EFC. | ||